LSI LSI53C895A, Technical Manual

Page: 268 / 364

6-8 Electrical Specifications
6.2 TolerANT Technology Electrical Characteristics
The LSI53C895A features TolerANT technology, which includes active
negation on the SCSI drivers and input signal filtering on the SCSI
receivers. Active negation actively drives the SCSI Request,
Acknowledge, Data, and Parity signals HIGH rather than allowing them
to be passively pulled up by terminators.
Table 6.14 provides electrical
characteristics for SE SCSI signals. Figures 6.3 through 6.7 provide
reference information for testing SCSI signals.
Table 6.14 TolerANT Technology Electrical Characteristics for SE SCSI Signals
Symbol Parameter Min
1
Max Unit Test Conditions
V
OH
2
Output high voltage 2.0 V
DD
V I
OH
=
−
7 mA
V
OL
Output low voltage V
SS
0.5 V I
OL
= 48 mA
V
IH
Input high voltage 2.0 V
DD
+0.3 V –
V
IL
Input low voltage V
SS
−
0.3 0.8 V Referenced to V
SS
V
IK
Input clamp voltage
−
0.66
−
0.77 V V
DD
= 4.75; I
I
=
−
20 mA
V
TH
Threshold, HIGH to LOW 1.0 1.2 V –
V
TL
Threshold, LOW to HIGH 1.4 1.6 V –
V
TH
–V
TL
Hysteresis 300 500 mV –
I
OH
2
Output high current 2.5 24 mA V
OH
= 2.5 V
I
OL
Output low current 100 200 mA V
OL
= 0.5 V
I
OSH
2
Short-circuit output high current – 625 mA Output driving low, pin
shorted to V
DD
supply
3
I
OSL
Short-circuit output low current – 95 mA Output driving high, pin
shorted to V
SS
supply
I
LH
Input high leakage – 20
µ
A V
DD
±5%, V
PIN
= 2.7 V
I
LL
Input low leakage
−
20 –
µ
A V
DD
±5%, V
PIN
= 0 V
I
PD
Power down leakage – 20 V
DD
= 0 V, V
PIN
= 1.2 V
R
I
Input resistance 20 – M
Ω
SCSI pins
4
C
P
Capacitance per pin – 15 pF PQFP
t
R
2
Rise time, 10% to 90% 4.0 18.5 ns Figure 6.3